FDA OKs a breakthrough antipsychotic from Acadia for Parkinson’s

Acadia Pharmaceuticals ($ACAD) has won its lengthy quest to gain an approval for Nuplazid (pimavanserin), a breakthrough antipsychotic that relies on a new mechanism of action to prevent hallucinations and delusions among Parkinson’s patients. 

The FDA formally approved Acadia’s marketing application on Friday evening--after missteps at the company triggered a long delay--setting up a planned June rollout of the new therapy. 

The drug is the first approved therapy that targets 5-HT2A receptors, so it shouldn’t interfere with the way Parkinson’s treatments spur production of dopamine to treat motor symptoms. And the same drug is being studied as an antipsychotic for Alzheimer’s, which could significantly increase its potential to earn blockbuster revenue for Acadia.

That upside, though, is practically baked into the biotech's stock price, which jumped a modest 7% this morning as the approval came through as expected by most analysts.

A recent roundup of top drugs in the clinic by Evaluate Pharma pegged potential 2020 sales of $841 million for Nuplazid, though several analysts expect it to break into the $1 billion-plus club in the next 5 years. The FDA helped burnish those blockbuster expectations by designating pimavanserin as a “breakthrough” drug back in 2014.

Leerink's Paul Matteis has said that the drug will likely cost $13,500 a year.

The drug's novel mechanism helped win over a large majority of FDA advisers, who voted 12 to two to back an approval, even though FDA insiders had flagged serious concerns about the risks associated with taking the drug. As expected, the agency is putting a black-box warning on the drug noting a significant increase in the risk of death among patients taking the drug.

Analysts have been bullish about the drug’s prospects, even with the potential risks. There are a million Parkinson’s patients in the U.S., and 50,000 new cases are diagnosed every year. Roughly 40% to 50% of those patients will suffer from hallucinations and delusions.

Acadia’s success will also likely buoy the hopes of other biotechs in the same field. The startup Axovant has a 5-HT2A inverse agonist called nelotanserin in the clinic for Parkinson’s as well as Lewy body dementia. That drug was originally tested by Arena Pharma as a new treatment for insomnia, but proved ineffective in the clinic. Arena later sold the drug to a parent company of Axovant.

“Hallucinations and delusions can be profoundly disturbing and disabling,” said Dr. Mitchell Mathis, director of the Division of Psychiatry Products in the FDA’s Center for Drug Evaluation and Research, in a release. “Nuplazid represents an important treatment for people with Parkinson’s disease who experience these symptoms.”

- read the FDA announcement